The present invention relates generally to permanent magnets and is particularly directed to strip magnets of the type which are used as holding magnets. The invention is specifically disclosed as pairs of strip magnets that exhibit increased shear force resistance by use of mechanical interlocking features, which provides additional holding capability.
Holding magnets have been available for years, and some of these magnets are extruded into strips. In many applications, these strip magnets are permanently attached to a structure, and then pieces of the structure are mated together at these magnets so as to form a temporary structure, such as a display stand used in a store. The holding magnets can be mated along their wide planar surfaces, or in some instances can be mated along their relatively thin edges. The magnetic force exerted will depend upon the materials used, the amount of magnetization, and the overall dimensions and polarizations of the magnets themselves.
While the strip magnets used in the past are adequate for many applications, they could still be improved upon, especially with respect to preventing the structures from coming apart due to shear forces.
Accordingly, it is an advantage of the present invention to provide a set of strip holding magnets to have improved shear force capabilities.
It is another advantage of the present invention to provide a set of strip magnets that have shaped edges or surfaces that provide some extra mechanical strength to aid in improving upon the shear force resistance capabilities while holding together.
Additional advantages and other novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention.
To achieve the foregoing and other advantages, and in accordance with one aspect of the present invention, a set of permanent magnets is provided, which comprises: a first substantially rectangular permanent magnet having a first substantially planar surface and a second, opposite substantially planar surface, a first edge, a second edge, a third edge, and a fourth edge which form a perimeter about the first and second surfaces; a second substantially rectangular permanent magnet having a third substantially planar surface and a fourth, opposite substantially planar surface, a fifth edge, a sixth edge, a seventh edge, and an eighth edge which form a perimeter about the third and fourth surfaces; the first magnet exhibiting at least one protrusion along at least a portion of the first edge; and the second magnet exhibiting at least one depression along at least a portion of the fifth edge; wherein the at least one protrusion and the at least one depression are sized and shaped so as to mechanically mate with one another when the first magnet is placed proximal to the second magnet in a manner that orients the first edge with the fifth edge.
In accordance with another aspect of the present invention, a set of permanent magnets is provided, which comprises: a first substantially rectangular permanent magnet having a first substantially planar surface and a second, opposite substantially planar surface, a first edge, a second edge, a third edge, and a fourth edge which form a perimeter about the first and second surfaces; a second substantially rectangular permanent magnet having a third substantially planar surface and a fourth, opposite substantially planar surface, a fifth edge, a sixth edge, a seventh edge, and an eighth edge which form a perimeter about the third and fourth surfaces; the first magnet exhibiting at least one protrusion along at least a portion of the first surface; and the second magnet exhibiting at least one depression along at least a portion of the third surface; wherein the at least one protrusion and the at least one depression are sized and shaped so as to mechanically mate with one another when the first magnet is placed proximal to the second magnet in a manner that orients the first surface with the third surface, thereby increasing a shear force capability of the set of permanent magnets.